Adjustable flat spinneret for the coextrusion of flat films comprising a plurality of components

ABSTRACT

Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of this conduit, and at least one substantially planar partition rotatably mounted in this conduit in the distal end thereof, the plane of these partitions being parallel with the axis of the conduit and the edges of the partition each terminating near the inside wall of the conduit. A process for producing composite films which may later be either monoaxially or biaxially drawn by coextruding a plastic film having a central area with two borderstrips having different compositions attached to each side of the running length of the central area. The films comprise a central area having at least two layers and a borderstrip having a composition different from the central area and attached to each running edge of the central area.

United States Patent [191 Riboulet et a1.

[ 51 Sept. 30, 1975 1 1 ADJUSTABLE FLAT SPINNERET FOR THE COEXTRUSION OF FLAT FILMS COMPRISING A PLURALITY OF COMPONENTS [75] Inventors: Robert Riboulet, Crepieus; Yves Galery, Saint Maurice de Beynost, both of France [73] Assignee: La Cellophane, Paris, France [22] Filed: Dec. 27, 1972 [21] Appl. No.: 318,778

[56] References Cited UNITED STATES PATENTS 2,761,418 9/1956 Russell 425/131 UX 3,072,624 1/1963 Akaboshi et al.. 259/6 X 3,489,178 1/1970 Kice 137/625.4l 3,560,430 2/1971 Meyer et a1 259/8 X 9/1973 Wight 425/133 X 7/1974 Hoagland et a1 425/131 [57] ABSTRACT Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of this conduit, and at least one substantially planar partition rotatably mounted in this conduit in the distal end thereof, the plane of these partitions being parallel with the axis of the conduit and the edges of the partition each terminating near the inside wall of the conduit. A process for producing composite films which may later be either monoaxially or biaxially drawn by coextruding a plastic film having a central area with two borderstrips having different compositions attached to each side of the running length of the central area. The films comprise a central area having at least two layers and a borderstrip having a composition different from the central area and attached to each running edge of the central area.

6 Claims, 19 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 of 2 "III/111111111 I ADJUSTABLE FLAT SPINNERET FOR THE COEXTRUSION OF FLAT FILMS COMPRISING A PLURALITY OF COMPONENTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved apparatus for regulating the feed to a coextrusion nozzle and further relates to an improved process for coextruding thin plastic films which are to be monoaxially or biaxially orientated and a product produced thereby. More particularly, this invention relates to an apparatus for use with a coextrusion nozzle which adjusts the orientation of the extrudable fluids so that the same may be so extruded into any desired configuration including a laminated relationship and a side-by-side relationship or combination thereof.

2. Brief Description of the Prior Art The coextrusion of a series of plastic materials into a laminated or layered plastic film is well known with representative apparatus being disclosed in the following U.S. Pat. Nos. 3,397,428, 3,308,222, 3,321,804, 3,494,993, 3,487,505 3,556,265, 3,480,998, 2,901,770, 3,223,761 and 3,464,087.

More particularly a recent flat end' feed coextrusion nozzle as disclosed in US. Pat. No. 3,476,627 has provided a simple and economicalnoz zle or spinneret for producing flat, two-component plastic films. However, due to the configuration of the nozzle as disclosed in this patent, it has become immediately apparent that the regulation of the angle at which the 'two polymers join forming the layered coextruded plastic film requires considerable adjustment in order to produce a coextruded flat film having an even crosssection.

Also it is often desirable to produce oriented thermoplastic films and it is a common expedient to include a selvagelike material on each end of the coextruded product so as to form a surface for the orientation grippers. This material is wasted material since it must be cut off and discarded subsequent to orientation. It has been proposed to reuse such material, however, the continued extrusion of these materials degrades the entire product since according to prior art processes the residue or selvage is mixed with the film forming material which is to form the entire coextruded sheet. An example of this type of process and product produced thereby is in US. Pat. Nos. 3,398,43l and 3,448,l83.

In each of the two above-noted processes, the selvage material which is to be cut off and re-utilized is one of the two components of the laminated thermoplastic film. Since the constant re-working of these selvage materials tends to degrade the same, this lowers the quality of the laminated extruded product since the selvage material which is cut off and recycled even if the same does not contain any additional mixed polymer, tends to be of a lower overall quality than the polymer initially extruded. g g g In addition to US. Pat. No. 3,476,627, the apparatus as disclosed in US. Pat. No. 3,528,130 is useful for making laminated flat extruded films. Basically, this apparatus comprises means to mix three separate polymer streams so that upon extrusion from a sheeting or film die, the product will have a uniform thickness and cross-section. Although this patent allows for a small amount of manipulation of the orientation of the various extruding orifices, the entire apparatus must be completely stopped before such adjustments can be made, thereby necessitating extended shut-downs in the equipment.

BRIEF DESCRIPTION OF THE INVENTION It is within the above environment and background that the apparatus, method for using the same and product produced therefrom of the present invention have been developed. Briefly, the apparatus of the present invention comprises apparatus for adjusting the flow of at least two fluids to a coextrusion nozzle comprising a generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of this conduit, and at least one substantially planar partition rotatably mounted in this conduit in the distal end thereof, the plane of each partition being parallel with the axis of the conduit and the edges of each partition terminating near the inside wall of the conduit.

The process of the present invention comprises a process for producing a multi-component film which may be later monoaxially or biaxially drawn with a minimum of waste by extruding a plastic film having a central area having two borderstrips with different compositions attached to each side of the running length of the central area, and later drawing or orienting the film and removing the edge portions from the finally drawn product. I

The product of the present invention comprises a flat composite thermoplastic film having a central area with at least two layers and two borderstrips attached one on each side of the running length of the central area, the borderstrips having a different composition than the central area.

OBJECTS AND ADVANTAGES It is therefore a primary object of the present invention to provide a method and apparatus for quickly and efficiently manufacturing laminated coextruded thermoplastic films having a substantially uniform crosssection.

It is a further object of the present invention to pro vide an apparatus wherein the angle of the thermoplastic melt may be readily and easily varied so as to obtain a final coextruded product having an even crosssection.

It is a still further object of the present invention to provide a method for producing a coextruded laminated thermoplastic film which may be monoaxially or biaxially drawn with a minimum of waste and product degradation.

It is still a further object of the present invention to provide a method for easily producing multicomponent thermoplastic films wherein the relationship of the various components may be easily changed and varied to obtain a desired cross-sectional configuration.

BRIEF DESCRIPTION OF THE DRAWINGS Still further objects and advantages of the apparatus, method and product of the present invention will become more apparent from the attached drawings and the following more detailed description thereof, wherein:

FIG. I is a diagrammatic side view of the apparatus of the present invention mounted for use in conjunction with an end feed, flat spinneret;

FIG. 2 is a view taken along line 2-2 in FIG. ll;

FIG. 3 is a view taken along line 33 in FIG. 1;

FIG. 4 is a diagrammatic side view of a further embodiment of the apparatus of the present invention;

FIG. 5 is a view along line 55 in FIG. 4;

FIG. 6 is a diagrammatic side view of a still further embodiment of the apparatus of the present invention;

FIG. 7 is a view taken along line 77 in FIG. 6;

FIG. 8 is a diagrammatic side view twisted 90 on the line XX for clarity of a still further embodiment of the apparatus of the present invention;

FIG. 9 is a view taken along line 9-9 in FIG. 8;

FIG. 10 is a view along line l0l0 in FIG. 8;

FIG. 11 is a view along line 1111 in FIG. 8;

FIG. 12 is a cross-sectional representation of a bicomponent thermoplastic film produced utilizing the apparatus of the present invention;

FIGS. 13 and 14 are cross-sectional views similar to FIG. 12 wherein the apparatus of the present invention has not been properly adjusted;

FIG. 15 is a cross-sectional view of the threecomponent film produced utilizing the apparatus of the present invention;

FIGS. 16 through 19 are cross-sectional views of films produced in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIGS. 1, 2 and 3, the apparatus of the present invention is shown in combination with an end feed flat spinneret 1 having a thin flat nozzle 2 for the extrusion of a flat laminated film. The control apparatus of the present invention is mounted at the end of generally cylindrical conduit 3 by any conventional connecting means 4.

Basically, the flow control apparatus of the present invention comprises a thin blade 5 which is mounted within the cylindrical conduit 6. Blade 5 is attached at its upper end to adjusting means 7 rotatably mounted in groove 8. The seal between adjusting means 7 and groove 8 is such that adjusting means 7 can be positioned as necessary yet prevents any leakage of polymer melt between groove 8 and adjusting means 7. On either side of cylinder 6 are product feed conduits 9 and 10 through which separate melts of thermoplastic materials are fed for extrusion through extrusion nozzle 2. Feed conduits 9 and 10 are each individually connected to conventional flow controlling means for regulating the flow of each polymer melt relative to the other.

Due to the asymmetrical shape of extrusion nozzle 2 with respect to the configuration of conduit 3, in order to obtain an even flow of both layers of thermoplastic material through nozzle 2, blade 5 must be adjusted so that it makes an angle theta with the line extending through the center of nozzle 2. This angle theta cannot be predicted and must be determined by trial and error since if the angle is not properly set, a film having the structure as shown in FIGS. 13 and 14 will be produced. The angle theta, such angle depending upon a number of factors including the exact shape of the extrusion nozzle 2, the relative viscosities of the thermoplastic melts and flow data of the melts which is dependent upon composition, temperature and pressure, can only be determined while the apparatus is on stream and is operating at steady state. Furthermore, if operating conditions change, the angle can be adjusted accordingly so as to compensate for the changes in feed conditions and thus maintain an even flow of thermoplastic melts across the nozzle 2 to obtain a product having a cross-section as shown in FIG. 12.

FIG. 2 shows the measurement of angle theta and diagrammatically shows the configuration of the thermoplastic melt passing through conduit 3 immediately before entering extrusion nozzle 2. FIG. 3 shows the positioning of blade 5 within conduit 6 between feed conduits 9 and 10. Furthermore, dotted lines 5' and 5 show the approximate maximum angle to which blade 5 can be adjusted. Furthermore, as shown, blade 5 extends substantially across conduit 6 with the clearance at each end being approximately 0.01 to 0.5 millimeters. This clearance is not critical as such, except that the clearance must be sufficiently close so as to prevent the melts from flowing around the edges of blade 5 and causing local areas of turbulence and non-laminar flow and yet the blade 5 must be sufficiently spaced from the wall so as to prevent any possible friction which might foul the equipment.

Furthermore, the extension of blade 5 down conduit 6 and its extension into conduit 3 is not particularly critical except that the length should be sufficient so as to insure sufficiently laminar flow of the two polymer melts as they combine at the end of blade 5. Blade 5 may be constructed from any sufficiently rigid material which is sufficiently smooth so as not to disrupt the laminar flow of the polymer melts flowing through conduits 6 and 3.

Referring to FIG. 4 which shows a second embodiment of the apparatus of the present invention wherein three separate polymers may be fed to the extrusion nozzle, the flow adjusting apparatus of the present invention is mounted on an extrusion nozzle feed conduit 3, such conduit being substantially similar to that as shown in FIG. 1. Feed conduit 3 may be any type of coextrusion nozzle wherein laminar flow is utilized to transport the various polymeric materials to their respective portions of the extrusion nozzle. The flow controlling apparatus is mounted on conduit 3 by any suitable connecting means 20 such as a threaded ring which joins feed conduit 3 with upper conduit 21. Both conduits of course should have the same internal diameter so as not to disrupt the laminar flow. Positioned within upper conduit 21 are two parallel blades 22 and 23 integral with rotatable adjusting member 24. Rotatable adjusting member 24 is attached to conduit 21 by any conventional rotatable mounting means such as extension 26 of conduit 21 which fits within groove 25 of member 24 to form a sufficient seal.

Conduit 27 is attached to the upper end of member 24. Conduit 27 has an internal diameter equal to the separation between parallel blades 22 and 23 and terminates at the upper end of blades 22 and 23. Further the axis of conduit 27 as it communicates with conduit 21 is the same as the axis of conduit 21. The embodiment as shown in FIG. 4 includes non-movable lateral side conduits 28 and 29 which are substantially perpendicular to the axis of conduit 21. By introducing a different polymer melt through each of conduits 27, 28 and 29, a three component film may be produced.

In FIG. 5 which shows a view alcn g line 55 the position of blades 22 and 23 can be seen with relation to conduits 27, 28 and 29. Again these blades extend substantially across conduit 21 so that there is a minimum of clearance at the edge so that laminar flow is maintained throughout the apparatus. The maximum adjustment of blades 22 and 23 is as shown by blades 22' and 23', i.e., when the blades are adjacent the openings in conduit 21 for conduits 28 and 29.

Referring to FIG. 6 which shows a third embodiment of the apparatus of the present invention, conduit 31 is mounted to inlet conduit 32 of an extrusion nozzle by means of connecting ring 33. In this embodiment rotatable member 34 which is mounted on the upper end of conduit 31 by means of groove 35 in member 34 and collar 36 in conduit 31 includes two separate feed conduits 37 and 38 which are connected to separate feed means so as to introduce two separate polymer melts into conduit 31. The lower endsof conduits 37 and 38 are connected to flat surfaces 39, 40 and 41 which are constructed in a manner similar to the dividing surfaces or blades as disclosed in FIGS. 1 and 4. As shown in FIG. 7, these dividing surfaces 39, 40 and 41 extend across conduit 31 so that there is minimal seepage of the polymer melts around the surfaces while retaining enough clearance so that no friction orjamming results during rotation. Conduit 31 also includes two additional feed inlets 42 and 43 which are connected to feed means to introduce at least one additional polymer melt into conduit 31. As with the other embodiments, the feed of the polymer melts is regulated so that the same are maintained in laminar flow with the relative velocity of each of the polymers being easily controlled in combination with the angle of rotation of member 34 with respect to the axis of the extrusion nozzle.

FIG. 8 shows a still further embodiment of the apparatus of the present invention, the apparatus having been turned 90 along line XX. Basically the apparatus as shown in FIG. 8 comprises the apparatus as shown in FIG. 4 including a generally cylindrical conduit 50 two feed means 51 and 52 mounted in conduit 50 and a rotatable member 53 mounted at one end of conduit 50, rotatable member 53 including a feed con duit 54 which terminates in two rigid members 55 and 56 mounted within conduit 50. Conduit 50 is attached by means of a ring attaching means 57 or any other suitable means to a rotatable member 58 which includes a flange 59 mounted in a U-shaped groove 60 at the top end of cylindrical conduit 61. Generally the diameter of conduit 61 is roughly equivalent to the internal diameter of conduit 50 which in turn is roughly equivalent or equal to the diameter of inlet conduit 62 of an extrusion nozzle. Conduit 61 is mounted on conduit 62 by means of a ring connection means 63 or any other similar means. Conduit 61 also includes two feed conduits 64 and 65 mounted in the sides of conduit 61 normal to the flow of melt through conduit 61. The internal diameter of member 58 is also roughly equivalent to the internal diameter of conduit 50. However, at a point below flange 59 two of the members of the generally cylindrical conduit 58 are flattened in an area 66 of decreasing diameter which terminates in two rigid flanges 67 and 68 which extend entirely across conduit 61 in a manner similar to members 55 and 56.

FIG. 9 which is a cross-sectional view taken along line 9-9 shows the orientation of members 55 and 56 in upper conduit 50 in relation to inlet conduits 51 and 52. FIG. shows the relationship of flat members 67 and 68 in relation to lower inlet conduits 64 and 65 in lower conduit 61. FIG. 11 is a cross-sectional view showing a cross-section of the polymer melt as it is moving in laminar flow through conduit 62 before introduction into an extrusion nozzle.

The process of the present invention which may advantageously use the apparatus of the present invention comprises coextruding a composite plastic film having a central area and a borderstrip along each running edge of the central area, so that the composite film may be monoaxially or biaxially oriented and the borderstrips subsequently removed.

The process of the present invention produces orientated plastic films with a minimum of waste of valuable film forming material. It is especially useful for orienting laminated or multi-component films since the edge or selvage portions of these films often cannot be recycled since they may contain a number of different and incompatible additives and continued recycling degrades the product. By using the preferred process of the present invention, which coextrudes a low cost selvage material for the orientation machine to contact, the selvage may be removed and discarded or recycled without product degradation.

The films of the present invention are those multilayer films which have a selvage formed from an inexpensive film forming polymer and comprise a central area having at least 2 layers each layer having a different composition and a border-strip attached to the central area along the running length of the central area, the borderstrip having a composition different from each of the layers in the central area. The preferred embodiment of the product of the present invention is where the width of the central area is large with respect to the border-strips.

The borderstrips and the central areas are joined through coextrusion and the intersection may either be perpendicular with respect to the surface of the films or at an angle of from 30 to with respect to the surface of the films. Since the composite film is to be oriented it is preferred that the intersection be an angle between 30 and 60 since the tendency of rupture clue to different stretchability is minimized.

As the layers of the central area any conventional film-forming compound may be used, such as polyesters, e.g., polyethylene terephthalate, polyolefins, e.g., polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyamides, polyvinyl butyl, etc.

Although at least two layers in the central area have a different composition, such difference may only result from different additives and modifiers. Often polymers include slip additives, dyes, etc., which are added to produce a film having a specific surface characteristic. Such additives are often costly and also detract from other properties of the film such as optical clarity, strength, etc. Accordingly, films within the present invention may include central areas having the same filmforming polymer, only having different modifiers in each layer.

As the borderstrip, polymers which are film-forming but are lower in cost, are used. Often these selvage polymers are lower molecular weight polymers which do not have desirable film-forming properties such as strength, etc. Accordingly, any waste or offspecification polymer which often will be discarded can be economically utilized as the borderstrips of the product of the present invention.

FIGS. 15 to 19 show cross-sectional views of plastic films produced utilizing the apparatus of the present invention and the process of the present invention with FIGS. 16 through 19 illustrating the composite films of the present invention. The film produced in FIG. 15

may be produced by utilizing the apparatus as shown in FIG. 4 using three different polymers, one each in conduits 27, 28 and 29 and adjusting the angle of rotation of member 24 such that a laminated coextruded film having three equal layers 90, 91 and 92 each having a different composition is produced.

FIG. 16 is a cross-sectional view of a thermoplastic film produced in accordance with the present invention. This film includes two selvage portions 100 and 101 joined to an intermediate product section 102. Although intermediate section 102 is shown as two superimposed layers 103 and 104, it may comprise either a single layer or a series of laminated or superimposed layers up to the limits of the equipment. As shown in FIG. 16., the line of intersection between areas 100 and 102 and areas 101 and 102 is at an angle, such angle being particularly important when biaxially and monoaxially oriented films are produced since the selvage areas 100 and 101 are usually produced from polymers having a lower degree of stretchability. It has been found that when utilizing polymers with different degrees of stretchability, an angle of intersection between the various areas of from 30 to 60 produces the best results with little, if any, separation between the central product area and the borderstrips.

FIG. 17 shows a second embodiment of the novel thermoplastic films of the present invention comprising a selvage area 105 and 106, these selvage areas being joined to the central area 107, having two superimposed layers 108 and 109, by lines of intersection perpendicular to the surface. As with the embodiment as shown in FIG. 16, subsequent to the stretching of the laminated thermoplastic film 107 the selvage areas 105 and 106 are removed and either recycled or eliminated since the same are produced from low cost polymers.

FIG. 18 shows a third embodiment of the films of the present invention wherein selvage areas 110 and 111 are extended on each running edge of central area 112 which includes three layers 113, 114 and 115. As in FIG. 16, the junction between the central area and the selvage area is at an angle so as to minimize the difference in stretchability between the selvage and central areas. When the monoaxial or biaxial orientation or stretching is completed both selvage areas 110 and 11 1 are removed thus producing thermoplastic film having a co-lamination of three layers with a minimum of waste of the valuable product polymers.

FIG. 19 is an embodiment similar to that shown in FIG. 18 wherein selvage areas 116 and 117 intersect central area 118 with a line of intersection perpendicular to the surfaces of the film. This embodiment is to be utilized when the stretchability of the selvage polymers is similar to that of the colamination central area and when it is desired to re-utilize the selvage polymer as often as possible since upon removal a minimum of product polymer is mixed with the selvage material.

While the apparatus, method and products of the present invention have been illustrated by way of the foregoing drawings embodiments and specific examples, the same are to be in no way limited thereto and are to be construed as broadly as any and all equivalents as set forth and properly defined in the following claims.

We claim:

1. Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a first generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of said conduit adjacent the distal end of said conduit, at least two of said feed means each comprising a feed conduit laterally extending from said cylindrical conduit, each of said feed means being spaced approximately from each other and at least one substantially planar partition rotatably mounted in said cylindrical conduit in said distal end thereof, the plane of said partition being parallel with the axis of said cylindrical conduit and the edges of said partition each terminating sufficiently close to the inside wall of said cylindrical conduit to prevent extrudable fluid from flowing around said edges wherein said discharge end of said first cylindrical conduit communicates with the inlet end of an end feed, flat extrusion nozzle.

2. The apparatus of claim 1, wherein there are two substantially planar partitions rotatably mounted in said conduit said two parallel partitions defining a volume within said conduit and said apparatus further including at least one additional feed means communicating with said volume defined by said parallel partitions, the axis of said at least one additional feed means being the same as the axis of said conduit. 7

3. The apparatus of claim 1, wherein there. is one sub stantially planar partition.

4. Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a first generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of said first conduit adjacent the distal end of said first conduit, at least two of said feed means each comprising a feed conduit laterally extending from said first conduit, each of said feed means being spaced approximately 180 from each other, two substantially planar partitions rotatably mounted in said first conduit in said distal end thereof, the plane of said partitions being parallel with the axis of said first conduit and the edges of said partitions each terminat- 1 ing sufficiently close to the inside wall of said first conduit to prevent extrudable fluid from flowing around said edges, said two parallel partitions defining a volume within said first conduit, at least one additional feed means communicating with said volume defined by said parallel partitions, the axis of each additional feed means being the same as the axis of said first conduit, saidadditional feedmeans comprising a second generally cylindrical conduit having a distal end and a discharge end, said discharge end directly communicating with the volume between said partitions and said distal end, at least two extrudable fluid feed means communicating with the interior of said second conduit adjacent the distal end thereof, at least two of said extrudable fluid feed means each comprising a feed conduit laterally extending from said second conduit, each of said feed means being spaced approximately 180 from each other and at least one substantially planar partition rotatably mounted in said second conduit in the distal end thereof, the plane of each planar partition in said second conduit being parallel with the axis of said second conduit and the edges of each partition each terminating sufficiently close to the inside wall of said second conduit to prevent extrudable fluid from flowing around said edges, the axis of said first and second conduits being the same, said discharge end of said first cylindrical conduit communicating with the inlet end of an end feed, flat extrusion nozzle.

feed means communicating with said volume defined by said parallel partitions.

6. The apparatus of claim 4, wherein there is one substantially planar partition in said second conduit.

l l =l 

1. Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a first generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of said conduit adjacent the distal end of said conduit, at least two of said feed means each comprising a feed conduit laterally extending from said cylindrical conduit, each of said feed means being spaced approximately 180* from each other and at least one substantially planar partition rotatably mounted in said cylindrical conduit in said distal end thereof, the plane of said partition being parallel with the axis of said cylindrical conduit and the edges of said partition each terminating sufficiently close to the inside wall of said cylindrical conduit to prevent extrudable fluid from flowing around said edges wherein said discharge end of said first cylindrical conduit communicates with the inlet end of an end feed, flat extrusion nozzle.
 2. The apparatus of claim 1, wherein there are two substantially planar partitions rotatably mounted in said conduit said two parallel partitions defining a volume within said conduit and said apparatus further including at least one additional feed means communicating with said volume defined by said parallel partitions, the axis of said at least one additional feed means being the same as the axis of said conduit.
 3. The apparatus of claim 1, wherein there is one substantially planar partition.
 4. Apparatus for adjusting the flow of at least two extrudable fluids to a coextrusion nozzle comprising a first generally cylindrical conduit having a discharge end and a distal end, feed means for each fluid communicating with the interior of said first conduit adjacent the distal end of said first conduit, at least two of said feed means each comprising a feed conduit laterally extending from said first conduit, each of said feed means being spaced approximately 180* from each other, two substantially planar partitions rotatably mounted in said first conduit in said distal end thereof, the plane of said partitions being parallel with the axis of said first conduit and the edges of said partitions each terminating sufficiently close to the inside wall of said first conduit to prevent extrudable fluid from flowing around said edges, said two parallel partitions defining a volume within said first conduit, at least one additional feed means communicating with said volume defined by said parallel partitions, the axis of each additional Feed means being the same as the axis of said first conduit, said additional feed means comprising a second generally cylindrical conduit having a distal end and a discharge end, said discharge end directly communicating with the volume between said partitions and said distal end, at least two extrudable fluid feed means communicating with the interior of said second conduit adjacent the distal end thereof, at least two of said extrudable fluid feed means each comprising a feed conduit laterally extending from said second conduit, each of said feed means being spaced approximately 180* from each other and at least one substantially planar partition rotatably mounted in said second conduit in the distal end thereof, the plane of each planar partition in said second conduit being parallel with the axis of said second conduit and the edges of each partition each terminating sufficiently close to the inside wall of said second conduit to prevent extrudable fluid from flowing around said edges, the axis of said first and second conduits being the same, said discharge end of said first cylindrical conduit communicating with the inlet end of an end feed, flat extrusion nozzle.
 5. The apparatus of claim 4, wherein there are two substantially planar partitions rotatably mounted in said second cylindrical conduit, said two parallel partitions defining a volume within said second cylindrical conduit and further including at least one additional feed means communicating with said volume defined by said parallel partitions.
 6. The apparatus of claim 4, wherein there is one substantially planar partition in said second conduit. 